1. Field of the Invention
The invention relates to integrated circuits, and particularly to computations for computer graphics.
2. Description of Related Art
Graphic software applications use floating-point instructions for computation of images in a computing system. An image is typically calculated using approximation to reduce processing time since the computation of floating-point instructions in graphics do not require the same level of precision as in scientific applications. For any floating-point computation, there are basically two separate, but related computations that need to be performed. The first portion is the computation of the result exponent. The second portion is the computation of the result mantissa.
A conventional approach performs a calculation of a reciprocal square root in two instructions. The first instruction computes the square root, and the second instruction computes a reciprocal of that square root. In one example, a system requires one clock cycle for each bit of mantissa, using about 48 clock cycles to complete the computation.
Accordingly, it is desirable to have methods and systems for computing floating-point instructions in reduced time while maintaining sufficient accuracy.